confdantic

Confdantic is a Python library that enhances Pydantic's capabilities for working with JSON, YAML, and TOML formats by preserving field descriptions as comments when serializing to YAML or TOML.

Installation

Using pip

pip install confdantic

Using uv

uv add confdantic

From source

pip install git+https://github.com/zigai/confdantic.git
# or
uv add git+https://github.com/zigai/confdantic.git

Example

from typing import Literal
from pydantic import Field
from confdantic import Confdantic

class DatabaseConfig(Confdantic):
    host: str = Field(
        "localhost",
        description="The hostname or IP address of the database server",
    )
    port: int = Field(
        5432,
        description="The port number on which the database server is listening.",
    )
    username: str
    password: str

class ApplicationConfig(Confdantic):
    debug: bool = Field(False, description="Enable debug mode")
    log_level: Literal["DEBUG", "INFO", "WARNING", "ERROR"] = Field(
        "INFO", description="Logging level"
    )
    database: DatabaseConfig
    allowed_hosts: list[str] = Field(
        default_factory=list,
        description="A list of host/domain names that this application can serve.",
    )

config = ApplicationConfig(
    database=DatabaseConfig(username="admin", password="secret"),
    allowed_hosts=["example.com"],
)
config.save("config.yaml", comments=True)
config.save("config.toml", comments=True)

config.yaml

debug: false  # Enable debug mode
log_level: INFO # Logging level | choices: DEBUG, INFO, WARNING, ERROR
database:
  host: localhost  # The hostname or IP address of the database server
  port: 5432 # The port number on which the database server is listening.
  username: admin
  password: secret
allowed_hosts:  # A list of host/domain names that this application can serve.
  - example.com

config.toml

debug = false # Enable debug mode
log_level = "INFO" # Logging level | choices: DEBUG, INFO, WARNING, ERROR
allowed_hosts = ["example.com"] # A list of host/domain names that this application can serve.

[database]
host = "localhost" # The hostname or IP address of the database server
port = 5432 # The port number on which the database server is listening.
username = "admin"
password = "secret"

License

MIT License